The provincial government says it is is partnering with Toronto Hydro to build a battery energy storage system for the Eglinton Crosstown light rail transit (LRT) line, which it asserts will increase the reliability of the line, lower operating costs, and reduce emissions.

The power system, equivalent to a large battery, will be located at the future site of Mount Dennis Station and the LRT maintenance and storage facility.

It will be capable of providing backup and emergency power to the LRT line for up to four hours in the event of a wide-spread power outage, and replaces previous plans for a natural gas facility, a government news release says.

The 19-kilomtere Crosstown LRT will be completed by 2021 and will connect Mount Dennis in the west with Kennedy Station in the east, with a 10-kilometre underground tunnel in its central section.

Crosslinx Transit Solutions is constructing the overall project. The government says the battery energy storage system will provide more environmental and operating cost savings than a natural gas powered facility. It will store energy that is generated during off-peak hours, such as at night, which is cheaper to purchase and produce. This energy is then available to supply energy needs during the day.